240 POWDERED VEGETABLE DRUGS 



28. (Fig. 47.) BENZOINUM. Benzoin. U. S. 



Gum Benjamin, E. Benzoe, G. Benjoin de Sumatra, Fr. 



The balsamic resin obtained from Styrax benzoin Dryander, and of 

 other species of Styrax, Styraceae. 



Brownish color. , 



Balsamic odor. 



Somewhat acrid. 



Pure gum benzoin is in mottled pieces. The poorer grades are in 

 marbled masses, more or less crumbly and brittle and contain a high 

 percentage of vegetable impurities. Dissolve a small amount in 

 alcohol and examine the sediment microscopically for the insoluble 

 impurities. A very small amount of the gum dissolved in hot acidu- 

 lated water will show numerous rings of benzoic acid crystal by the 

 micro-sublimation test. 



Ash should not exceed 2.50-per cent. 



j' Not generally intentionally adulterated. The impurities may be 

 excessive. Vegetable impurities should not exceed 10 per cent. 



